Can I set up other businesses or other sub business through quickbook

One QBO account is for one company file. Should you need to manage branches or divisions of your company, you may utilize the Class and/or Location feature available in QBO Plus and Advanced.

https:// quickbooks.grsm.io/US
https:// quickbooks.grsm.io/us-promo

Another option, consider switching to QBD to manage multi company files with a single license.